Exposure Assessment for a Field Investigation of the Acute Respiratory Effects of Metalworking Fluids. I. Summary of Findings

• Published in: American Industrial Hygiene Association journal Vol. 57; no. 12; pp. 1154 - 1162
• Main Authors: Woskie, Susan R., Virji, Mohammed Abbas, Kriebel, David, Sama, Susan R., Eberiel, David, Milton, Donald K., Hammond, S. Katharine, Moure-Eraso, Rafael
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Fairfax, VA American Industrial Hygiene Association Journal 01.12.1996; American Industrial Hygiene Association; Taylor & Francis Ltd
• Subjects: Acute Disease; Aerosols; Air Microbiology; Air Pollutants, Occupational - adverse effects; Air Pollutants, Occupational - analysis; Analysis of Variance; Applied sciences; Atmospheric pollution; Automotive parts; Bacillus; Bacteria; Case-Control Studies; endotoxin; Environmental Monitoring; Exact sciences and technology; Fatty acids; Fluids; Forced Expiratory Volume; Health hazards; Humans; Indoor pollution and occupational exposure; Industrial Oils - adverse effects; Industrial Oils - analysis; machining; Manufacturing; Metallurgy; Metals; Metalworking industry; Mineral oils; Occupational Diseases - chemically induced; Occupational safety; Particle size; Pollution; Pseudomonas; Respiration Disorders - chemically induced; Respiratory diseases; Standard deviation; Studies; Sulfur; Workers; United States > US; Elementary analysis; Suspended particle; Ambient air concentration; Respiratory disease; Aerosols; Metalworking oil; Bacteria; Mineral oil; Microorganism; Occupational exposure; Endotoxin
• ISSN: 0002-8894; 2163-369X
• DOI: 10.1080/15428119691014279

The exposure assessment summarized here is part of an epidemiologic study of the acute respiratory health effects of metalworking fluid (MF) exposures. Exposures were measured as the inhalable concentrations of the MF aerosol, a variety of metals and elements, and endotoxin as well as the level of culturable bacteria in the aerosol size fraction less than 8 µm. Bulk samples of soluble MFs were tested for pH, mineral and tramp oil fraction, endotoxin, culturable bacteria, and lipopolysaccharide levels. The MF exposed workers had higher geometric mean inhalable aerosol exposures (0.181 mg/m 3 ) than the MF unexposed workers (0.046 mg/m 3 ). The MF exposed workers had higher geometric mean (GM) airborne culturable microbial counts (102 colony-forming units (CFU)/m 3 for bacteria <8 µm) than the unexposed workers (GM=14 CFU/m 3 ). Among the unexposed, Bacillus was the predominant airborne species, while among the exposed workers, Pseudomonas predominated. Exposed workers also had higher geometric mean airborne endotoxin levels (GM=7.1 endotoxin units (EU)/m 3 ) than the unexposed workers (GM=1.9 EU/m 3 ). Elemental concentrations of iron, chlorine, and sulfur were substantially higher among the exposed workers compared to the unexposed workers. For soluble metalworking fluids, the levels of bulk constituents were examined by three categories of time since the machine sump was refilled with fresh MF (<4 days, 4-21 days, >21 days). Univariate analyses of percent oil, pH, culturable bacteria, tramp oil percent, endotoxin, or fatty acid levels all showed no statistically significant changes in level over time.